In my opinion you have been doing far too much jumping around the game engines. If you would have chosen one game engine and focused on it continuously, then you would probably have several games published by now, perhaps even making some income.
Also I feel that you are at a level where you can not take solid advantage of any performance benefit of one game engine over another and probably not for years to come, so don't be concerned too much about game engine performance.
You can use place holder art which can be aquired at low cost or no cost so your game development progresses well until you either gain art skills or find a devoted artist. Some artists or art asset companies offer a few of their products at no cost until your game actually earns money by sales. There are thousands of 2D and 3D art assets which are open source license.
Here at game dev, there are a couple places to establish yourself. The classifieds can be used to find an artist. You can also use the Journal section to let people follow your progress, provide another place for prospects to get the information to decide if they want to join you, and demonstrate a seriousness to people about your project. If you participate in screenshot contests, a lot of people will see your progress - even with placeholder art.
Another recommended thing to do is launch your own game developer website and direct traffic there in many ways. Later when you have at least a demo game, then you can join contests or other marketing campaigns to generate more buzz about your work. This attracts artists and all kinds of people if you let them know.
The bottom line: Stay with this engine and really work it good for several years.